KR102274861B1 - Apparatus and Method for Detector of One way Delay of Protective Information Signal - Google Patents

Abstract

The present invention relates to a one-way delay detection device of a system protection signal that allows a one-way delay between protection relays that transmits and receives system protection signals to be monitored in real-time for smooth maintenance and management of the protection relay board through an optical terminal device for transmission and distribution, and allows an alarm to be raised when a certain threshold is exceeded; and has an objective of improving a degree of stability of a power system by providing a function to detect and restore a phase of the original signal even when 1PPS is unstable due to a momentary failure or failure of a clock synchronizing device and the like.

Description

Apparatus and Method for Detector of One way Delay of Protective Information Signal

The present invention relates to a one-way delay detection device for a system protection signal for detecting a one-way delay of a system protection signal transmitted and received in an optical terminal device for transmission and distribution, which is a power communication network.

The power produced by the power plant is converted into power at the substation and transmitted to the consumer. That is, a transmission line or a distribution line is installed between substations, which are complexly distributed regionally.

If a failure occurs in the power system of the transmission/distribution line, the failure in the failure section spreads to sections other than the occurrence of the failure, resulting in problems such as wide-area blackout and low voltage.

As such, in order to prevent the failure of the faulty section from spreading to the healthy section, a digital relay is applied as a device to separate the faulty section from the power system by determining the faulty state of the transmission line. In addition, a system protection transmission device for transmitting and receiving a system protection signal between relays of the transmission lines is applied to both ends of the transmission line for more accurate blocking. The grid protection transmission device installed at one end (own station) of the transmission line transmits the grid protection signal to the grid protection transmission device of the other end (opposite station) of the transmission line so that the digital relay at the other end of the transmission line operates.

However, since these system protection transmission devices do not have a function to measure, record, and warn of real-time transmission delay, in the actual field, transmission delay occurs due to problems with the digital optical transmission path or other system protection transmission devices themselves, and this is Although the transmission line was not normally protected due to a problem in transmitting and receiving the transmission line protection signal, the system protection transmission device that caused the problem could not detect it. In addition, even if both the transmission and reception delay times are within 5 ms, the transmission and reception paths may be different on the digital optical transmission path, so there may be a difference between transmission and reception. could cause problems.

Therefore, in order to improve this problem, in the related art, not only accurately measuring and detecting the transmission/reception delay of a digital signal transmitted and received between the grid protection transmission devices in real time, but also the transmission delay time between the transmission path and the reception path on the digital optical transmission path between the grid protection transmission devices There is provided a transmission delay detection device for a system protection transmission device, which can detect a transmission delay error caused by a system protection transmission device or a digital optical transmission path by accurately detecting the difference between

A transmission delay detection device for a system protection transmission device according to the prior art is disclosed in Korean Patent Publication No. 10-2014-0054889 (published on May 9, 2014).

1 is a block diagram of a transmission delay detection device for a system protection transmission device according to the prior art, which is connected to a first system protection transmission device 10, generates a master clock and transmits it through a first communication network (Ethernet network), , a master detector 10 for generating a first pattern signal based on the master clock; and a second system protection transmission device (2), generating a slave clock and synchronizing it with the master clock transmitted through the first communication network (Ethernet network), and based on the synchronized slave clock, a second pattern and a slave detector 20 that generates a signal and transmits it to the master detector 10 through a second communication network (digital optical transmission path).

The master detector 100 includes a master clock generator 11 for generating the master clock; a pattern generator 12 for generating a first pattern signal based on the master clock; a transmission delay measurement unit 13 for measuring the first delay time between the first pattern signal and the second pattern signal transmitted from the slave detector 20; and a delay comparison unit 14 that compares the measured first delay time with a reference delay time and generates a warning when the first delay time exceeds the reference delay time.

The slave detector 20 includes a slave clock generator 21 for generating the slave clock; a pattern generator 22 for generating the second pattern signal based on the slave clock; a transmission delay measurement unit 23 for measuring a second delay time between the first pattern signal transmitted from the master detector 10 and the second pattern signal; and a delay comparison unit 24 that compares the measured second delay time with the reference delay time and generates a warning when the second delay time exceeds the reference delay time.

The transmission delay detection device for a system protection transmission device according to the prior art configured as described above accurately measures and detects the transmission/reception delay of a digital signal transmitted/received between the system protection transmission devices in real time, as well as transmission on the digital optical transmission path between the system protection transmission devices. By accurately detecting the difference in transmission delay time between the path and the receiving path, it is possible to detect a transmission delay error caused by the system protection transmission device or the digital optical transmission path.

However, the transmission delay detection device for the system protection transmission device according to the prior art requires an Ethernet communication line for synchronization and the first and second communication networks that are digital optical lines for transmitting pattern signals to detect transmission delay, and clock information is embedded The delay time is detected by calculating the time difference between the first and second pattern signals, which is difficult to implement in a single transmission network, and there is no 1PPS restoration function in case of a temporary failure of time information, etc. There was a limit in providing a stable one-way delay value. .

Domestic Patent Publication No. 10-2014-0054889 (published on May 09, 2014)

Therefore, the present invention monitors in real time the one-way delay between the protection relays that send and receive system protection signals for the smooth maintenance and management of the protection relay through the optical terminal device for transmission and distribution for more stable maintenance than the prior art, and sets a specific threshold value. One-way delay of the system protection signal that raises an alarm when it exceeds and improves the stability of the power system by providing a function to detect and restore the phase of the original signal even when 1PPS is unstable due to a momentary failure or failure of the clock synchronizer, etc. An object of the present invention is to provide a detection device.

In order to achieve the above object, the one-way delay detection device of the system protection signal according to the present invention is a one-way delay of the system protection signal transmitted and received between the first and second optical terminal devices for transmission and distribution for transmitting the system protection signal of the protection relay In the device for detecting a signal, the first transmission and substation terminal device comprises: a reference signal generator for generating a master clock and a 1PPS (Pulse Per Second) signal; a time information encoding unit for generating time information for multiplexing the master clock and the 1PPS signal of the reference signal generator into a frame; a multiplexing unit for multiplexing the time information generated by the time information encoding unit with a system protection signal; a packet conversion and optical transmission/reception unit for transmitting the signal multiplexed by the multiplexer to the second optical terminal device for transmission and distribution and receiving the multiplexed signal transmitted from the second optical terminal device for transmission and transformation; a demultiplexer for demultiplexing packet data from the second optical terminal device for transmission and transformation received through the packet conversion and optical transceiver unit to extract a system protection signal and time information; a time information detection unit for extracting the time information extracted from the demultiplexer and detecting a time deviation from the time information value; and a one-way delay measurement unit that detects a one-way delay by calculating the deviation from the time detected by the time information detection unit with the time information of the other station based on the 1PPS signal of the own station. do.

Here, the second transmission and substation terminal device is characterized in that it has the same configuration as a counterpart station of the first transmission and distribution terminal device.

As described above, since the one-way delay detection apparatus of the system protection signal according to the present invention is encoded by the time information encoding unit and transmitted to the other station, there is an effect that the detection accuracy for the input 1PPS can be increased, and the transmission/transmission terminal of the own station and the other station The time information detection unit of the device receiving unit inversely encodes the encoded time information, and as soon as the corresponding deviation information is received, the detection accuracy can be improved by subtracting the received deviation value from the local time information calculated in the input section. It is possible to improve the detection accuracy by converting the deviation value into information and transmitting it, and correcting it at the receiving side.

In addition, the one-way delay detection device continuously monitors the 1PPS input, which is the standard for one-way delay measurement, and immediately generates a 1PPS alarm in case of a failure such as a short circuit of the 1PPS input, and remembers the point where 1PPS occurred to signal the 1PPS holdover signal. There is a function that can prevent the error of the one-way delay measurement value through the function of generating , and it monitors the period of the 1PPS signal, and if 1PPS is not input within ±20㎲ compared to the previous value, an alarm is immediately generated and the master clock It has the effect of preventing a one-way delay measurement error by generating its own 1PPS signal with a signal synchronized with

In addition, the present invention converts the first communication network, which is a conventional digital optical line, by applying the RFC 4553-based SAToP (Structure-Agnostic Time Division Multiplexing) function, so that the function can be implemented as a single transmission network, and temporary failures such as time information It has the effect of providing a stable one-way delay value through the restoration function of 1PPS.

1 is a block diagram of a transmission delay detection device for a system protection transmission device according to the prior art;
2 is a block diagram of an apparatus for detecting one-way delay of a system protection signal according to an embodiment of the present invention;
3 is a detailed block diagram of the one-way delay measurement unit in FIG. 2;
4 and 5 are one-way delay measurement timing diagrams,
6 is a timing diagram for explaining time deviation information according to 1PPS and E1 frame period;
7 is an operation flowchart of a transmission process of transmission delay detection devices for transmission and substation for first and second transmission;
8 is an operation flowchart of a reception process of the transmission delay detection apparatus for transmission and substation 1 and 2;

The present invention will become more apparent by describing in detail preferred embodiments of the present invention with reference to the accompanying drawings.

2 is a block diagram of an apparatus for detecting one-way delay of a system protection signal according to an embodiment of the present invention, wherein the first and second terminal devices 10 and 20 for transmission and distribution for transmitting the system protection signal of the protection relay are master A reference signal generator 100 and 200 that generates a clock and 1PPS signal, and a time information encoder that generates time information in which the master clock and 1PPS signal of the reference signal generator 100 and 200 are multiplexed into a frame (110) (210), a multiplexing unit (120, 220) for multiplexing the time information generated by the time information encoding unit (110, 210) together with a system protection signal, and the multiplexing unit (120, 220) ) transmits the multiplexed signal to the optical terminal device 10, 20 for transmission and transformation of the opposite station, and a packet conversion and optical transmission/reception unit 160 for receiving the multiplexed signal transmitted from the terminal device for transmission and transformation of the opposite station (10, 20) ) 260 and the packet conversion and optical transmission/reception unit 160, 260 to demultiplex the packet data from the first or the optical terminal device for transmission and transformation of the opposite station to extract the system protection signal and time information The demultiplexing unit 150 and 250, and the time information detecting unit 130 and 230 for extracting the time information extracted from the demultiplexing unit 150 and 250, and detecting a deviation from the time information value with respect to time and a one-way delay measurement unit 140 that detects the one-way delay by calculating the deviation for the time detected by the time information detection unit 130 and 230 with the time information of the other station based on the 1PPS signal of the own station. do.

Here, the first and second optical terminal devices 10 and 20 for transmission and substation transmit the system protection signal of the protection switchboard in the PCM (Pulse Code Modulation) data format of the G.703 or C37.94 standard according to the connection standard. It is a device for transmitting and receiving, and each configuration (210 to 260) of the second optical terminal device for transmission and distribution 20 is configured to be symmetrical with each configuration (110 to 160) of the first optical terminal device for transmission and distribution 10, and each part Since it performs the same means and functions as the name of , the detailed configuration and operation of the second optical terminal device for transmission and distribution 20 refer to the description of the first optical terminal device for transmission and distribution 10 .

3 is a detailed block diagram of the one-way delay measurement unit 140. The one-way delay measurement unit 140 receives a 1PPS signal from the reference signal generator 100 and sets a resolution based on a rising edge. ), the counting unit 141 that counts up, and the one-way delay value by comparing the count value received from the counting unit 141 and the time period value of the encoding value calculated by the first time information detecting unit 130 It consists of a one-way delay calculating unit 142 and a central processing unit 143 that generates an alarm when the one-way delay measurement value calculated by the one-way delay calculating unit 142 exceeds a preset threshold value.

An embodiment of the present invention configured as described above will be described in detail with reference to the accompanying FIGS. 2 to 8 as follows.

First, the present invention operates a protection relay for the purpose of preventing the spread of the failure when a power accident such as a ground fault or short circuit occurs in a power facility such as a transmission or substation, or a failure occurs at any one point. Through the dedicated optical terminal device, it is possible to monitor the local output current and the incoming current in real time by transmitting and receiving the grid protection signal of the local protection relay and the other station protection relay.

If an asymmetric one-way delay occurs in the process of sending and receiving the grid protection signal for this current magnitude, the relay generates an alarm because it may cause an error in the magnitude and phase information of the current and may cause unnecessary malfunction. It is managed as a major item of optical terminal devices.

The one-way delay detection device of the optical terminal device for transmission and distribution monitors in real time the one-way delay between the protection relays that send and receive system protection signals for the smooth maintenance and management of the protection relay and generates an alarm when a specific threshold is exceeded. In addition, even when the 1PPS signal is unstable due to a momentary failure or failure of a clock synchronization device, etc., it provides a function to detect and restore the phase of the original signal, thereby improving the stability of the power system.

Referring to FIG. 2, the present invention is applied to an optical terminal device for transmission and distribution, which is a system protection signal transmission device of the protection relay, and is a device for detecting one-way transmission delay between each terminal device. In 10), time synchronization within ±1 μs is achieved using IEEE 1588v2 PTP (Precision Time Protocol), and encoding information for one-way delay is generated based on the 1PPS signal generated based on this, and this is multiplexed to the E1 frame. The one-way delay is calculated based on the encoding information received from the second optical terminal device 20 for transmission and distribution through the Ethernet network to the second optical terminal device 20 for transmission and distribution, which is an interlocked counterpart station, based on the 1PPS information of the host station. and measure

The Ethernet network is based on IEEE 802.3, and the High-availability Seamless Redundancy (HSR) protocol for lossless optical fiber switching function is applied, and the RFC 4553-based SAToP (Structure-Agnostic Time Division Multiplexing) function is applied to the digital optical fiber network. It is applied to convert packets, so it can be implemented as a single transmission network.

7 is an operation flowchart of a transmission process of a system protection signal one-way delay detection apparatus according to an embodiment of the present invention. Referring to this, the reference signal generator 100 generates a master clock and generates a reference 1PPS signal such as GPS. and transmits it to the time information encoding unit 110 .

The time information encoding unit 110 generates time information to be multiplexed into the E1 frame, inputs it to the multiplexer 120, is multiplexed with a system protection signal in the multiplexer 120, and then performs packet conversion and optical transmission/reception unit It is transmitted to the second optical terminal device for transmission and substation, which is a counterpart station through (160).

In more detail, the time information encoding unit 110 encodes the 1PPS input from the reference signal generator 100 to increase detection accuracy and transmits it to the other station, and the encoded time information is multiplexed into the E1 frame. It has 4 bits of time deviation information. Since the E1 frame of one period is 125 μs, the encoded time information is multiplexed once every 125 μs, and has a maximum one-way delay error of 125 μs depending on the input time of 1PPS.

In order to reduce the one-way delay detection error as described above, the 125 μs frame period is divided into 15 sections, and it is encoded by determining in which section the 1PPS signal is input based on the E1 frame, so the detection accuracy is increased up to 8.333 μs.

That is, among 15 sections, the first section is set as time information “01”, the second section is set as time information “02”, and the 15th section is sequentially set as time information “15”.

Meanwhile, the value of the section corresponding to the time when the 1PPS is input is encoded into 4 bits and transmitted to the multiplexer 120 .

4 and 5 are timing diagrams for explaining time deviation information according to 1PPS and E1 frame period. According to 1PPS input that does not match the E1 frame period and E1 frame period, in FIG. 4, time information '3' is added to the E1 frame. It is multiplexed and transmitted, and in FIG. 5, time information 'C' is multiplexed and transmitted.

In a general case, the presence or absence of 1PPS is indicated in the corresponding frame using one overhead. Therefore, the one-way delay measurement value of FIGS. 4 and 5 measured at the receiving side is the same even though the input position of 1PPS is different. However, in the present invention, when the deviation time information is transmitted by subdividing the corresponding section, as shown in FIG. 4, "time information 3 x 1 section value 8.333 μs = correction value 25 μs", in the case of " Since the time information 12 x 1 section value 8.333㎲ = correction value 100㎲" has a correction value, a more approximate one-way delay value is measured.

8 is an operation flowchart of a reception process of the system protection signal one-way delay detection apparatus according to an embodiment of the present invention. Referring to this, the multiplexing unit 150, the time information detection unit 130, and the one-way delay measuring unit constituting the receiving unit are shown. The E1 frame received from the second optical terminal device 20 for transmission and distribution, which is the counterpart station through 140, is demultiplexed through the demultiplexer 150, and the encoded time information is de-encoded to convert the corresponding deviation information to the time. It is transmitted to the information detection unit 130 .

The time information detecting unit 130 extracts the demultiplexed and decoded system protection signal and time information through the demultiplexing unit 150, and the one-way delay measuring unit 140 converts the time information into its own 1PPS signal. , and the detection accuracy is improved by subtracting the received deviation value from the calculated time information of the own station as soon as the deviation information is received.

3 and 6, the one-way delay measurement unit 140 will be described in detail as follows.

The 1PPS signal generated by the reference signal generating unit 100 is supplied to the time information encoding unit 110 of the transmitting unit and the counting unit 141 of the receiving unit, and the counting unit 141 is a rising edge of the received 1PPS signal. Count up with 1㎲ resolution based on (Rising Edge).

Meanwhile, the time information encoding unit 110 divides the DS-1E 125 μs frame period multiplexed and transmitted by the multiplexer 120 into 15 sections, and encodes the value of the section corresponding to the time when 1PPS is input into 4 bits. After that, it is multiplexed and transmitted.

Here, the encoding value has a value ranging from ‘0b0001 to 0b1111’, and each encoding value corresponds to a value ranging from 7.813 μs to 117.195 μs.

When a value other than '0' is detected in the encoding value received from the second optical terminal device 20 for transmission and distribution, the counter unit 141 of its own station stops counting up and latches the current count value, so that the one-way delay operation unit (142), the encoding value received from the time information detecting unit 130 is converted into a time period value and applied to the one-way delay calculating unit 142.

The one-way delay calculation unit 142 calculates a one-way delay value by subtracting the period value calculated by the time information detection unit 130 from the latched count value of the local station.

That is, the one-way delay measurement value is calculated as "count value-(period value x7.8125㎲)".

The central processing unit 143 generates an alarm when the one-way delay measurement value exceeds the one-way delay threshold value set by the operator.

6 is a one-way delay measurement timing diagram according to an embodiment of the present invention. For example, a 1PPS signal is input in 3/15 section of the E1 frame period, and the code value “0101” transmitted by the other station at 500 μs from the input. When this is detected, since the 1PPS signal is input in the 3/15 section of the E1 frame period, the code value “0011” is generated and transmitted to the next frame. At the same time, it counts up with a clock having a period of 1 μs based on the rising edge of 1 PPS. From the point of the falling edge of 1PPS, the code value "0000" is transmitted until before the next rising edge.

If the code value transmitted by the other station is detected at the point of 500 µs, the local station counts and latches the value. Since the code value transmitted by the other station is “0101”, a value of 461 μs obtained by subtracting the 39 μs value corresponding to the counterpart station code value “0101” from the self-counted value of 500 μs is applied to the register as a one-way delay measurement value.

The central processing unit 143 polls the corresponding register value and generates an alarm when the measured value exceeds a preset threshold value.

As described above, although the one-way delay detection device of the system protection signal according to the present invention has been described with reference to a limited embodiment and drawings, it is not limited by this embodiment, and a person of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the technical spirit of the present invention and equivalents of the claims to be described below.

10, 20: Optical terminal device for first and second transmission and substation
100,200: reference signal generator 110,210: time information encoder
120,220: Multiplexing unit 130,230: Time information detecting unit
140,240: one-way delay measuring unit 150,250: demultiplexing unit
160,260: packet conversion and optical transmission/reception unit 141: count unit
142: one-way delay calculation unit 143: central processing unit

Claims (10)

An apparatus for detecting a one-way delay of a system protection signal transmitted and received between the first and second optical terminal devices for transmission and distribution for transmitting the system protection signal of the protection relay,
The first terminal device for transmission and transformation includes: a reference signal generator for generating a master clock and a 1PPS (Pulse Per Second) signal;
a time information encoding unit generating time information for multiplexing the master clock and the 1PPS signal of the reference signal generator into a frame;
a multiplexing unit for multiplexing the time information generated by the time information encoding unit with a system protection signal;
a packet conversion and optical transmission/reception unit for transmitting the signal multiplexed by the multiplexer to the second optical terminal device for transmission and distribution, and receiving the multiplexed signal transmitted from the second optical terminal device for transmission and transformation;
a demultiplexer for demultiplexing packet data from the second optical terminal device for transmission and transformation received through the packet conversion and optical transceiver unit to extract a system protection signal and time information;
a time information detection unit for extracting the time information extracted from the demultiplexer and detecting a deviation with respect to time from the time information value; and
A one-way delay measurement unit that detects a one-way delay by calculating the deviation for the time detected by the time information detection unit with the time information of the other station based on the 1PPS signal of the own station; Tonsil delay detection device. According to claim 1,
The one-way delay detection device of the system protection signal, characterized in that the reference signal generator performs time synchronization using the 1PPS signal of GPS. 3. The method of claim 2,
The first and second transmission and substation terminals achieve time synchronization within ±1 μs using the IEEE 1588v2 PTP (Precision Time Protocol) protocol, and measure the one-way delay based on each generated 1PPS signal, characterized in that One-way delay detection device of system protection signal. According to claim 1,
The time information encoding unit receives the 1PPS signal from the reference signal generator, divides the frame period of the signal being multiplexed and transmitted by the multiplexer into a certain section, and encodes the time information at the point in time when 1PPS is input into a set bit to multiplex the signal. One-way delay detection device of the system protection signal, characterized in that applied negatively. 5. The method of claim 4,
The time information encoding unit divides the 125 μs frame period transmitted from the multiplexer into 15 sections, and encodes the value of the section corresponding to the 1PPS input time into 4 bits,
The multiplexer has 4-bit time deviation information on the time information encoded by the time information encoding unit, and as it is multiplexed into an E1 frame of 125 μs per cycle, the encoded time information is multiplexed once every 125 μs One-way delay detection device of the system protection signal. According to claim 1,
The second transmission and substation terminal device is a counterpart to the first transmission and substation terminal device, and has the same configuration as the first transmission and substation terminal device. According to claim 1,
The one-way delay measurement unit continuously monitors based on the received 1PPS signal, and when there is a failure of the 1PPS input, immediately generates a 1PPS alarm, and remembers the point where 1PPS occurred to generate a 1PPS holdover signal. One-way delay detection device of the system protection signal, characterized in that. According to claim 1,
The one-way delay measurement unit includes: a counting unit for receiving a 1PPS signal from the time reference signal generator and counting up to a resolution set based on a rising edge; and
One-way delay detection apparatus of a system protection signal, characterized in that it comprises a one-way delay calculation unit for calculating a one-way delay value by comparing the time period value of the encoding value calculated by the count value and the time information detection unit with the count value received by the counting unit . 9. The method of claim 8,
When the encoding value transmitted from the other station is detected through the time information detecting unit, the counting unit stops counting up, latches the count value, and applies it to the one-way delay operation unit,
The time information detecting unit converts the encoding value received from the counterpart station into a time period value and applies it to the one-way delay calculating unit. 9. The method of claim 8,
The one-way delay detection device of the system protection signal, characterized in that it further comprises a central processing unit for generating an alarm when the one-way delay measurement value calculated by the one-way delay calculation unit exceeds a preset threshold value.

Images